Professor Membrane

Professor Membrane is the owner of the smartest mind in the universe of Invader Zim, and is the father of the show's main protagonists/antagonists, Dib and Gaz.

the actor, Rodger Bumpass who voiced him also voiced Squidward from Spongebob Squarepants, Pig from CatDog, Mosquito from A Bug's Life, and Brusier Bukowski from Cars, 

Role in the show
Membrane's appearances in the show are very minor and uncommon, but he still sometimes makes impacts in certain episodes. Being the one of the most important people on Earth due to his amazing engineering, Membrane is the father of Dib and Gaz. However, he is usually at his labs making scientific breakthroughs, so he is commonly replaces by a floating monitor of himself to serve and supervise his children. It is assumed that Dib and Gaz were genetically engineered by Membrane in an experiment, the hints being that there is no Mrs. Membrane and the two children have unexplained superpowers. He also has a grudge against Santa Claus as, on one Christmas Eve, Claus never gifted him any Uranium-238, so he helped Dib assassinate Saint Nick (while it was really Zim in disguise).

Powers
Like most scientists, Membrane is a genius and has made so many scientific breakthroughs and technological advances that he is one of the most important people on Earth. He is also a master engineer who can create anything and can cure almost any disease with his amazing skills in medicine and genetic science. He can also fire beams of light out of his gloves, probably due to a random experiment he conducted on himself.